The study showed that the average speed increased on the roadways to just slightly higher than the speed limit, which was expected, but it came at a cost.

Brad Wieferich, director of MDOT’s Bureau of Development told The Bridge:

“Greater speed automatically provides greater risk. The cars are way better than they used to be — better braking, better handling, better from an overall safety perspective. But at the end of the day, it’s still physics. Speed is distance over time… and with everyone on their cellphone that I see on the freeways, I would bet that our reaction times are worse.”

Crash records analyzed by Bridge paint a complicated picture of the early safety impact on freeways where speed limits were increased to 75 mph in May 2017.

Crashes jumped to 4,264 in 2018 on those freeways, the most in five years and up 17 percent from the annual average of 3,637 from 2014 to 2016.

Of the 2018 crashes, 589 involved an injury, the highest in five years and up 19 percent from the average from 2014 to 2016, while there were 14 crashes in which at least one person died, up from an average of 11 over the same period.

By comparison, crashes rose just 3 percent on all Michigan roadways over the same span, while the number of crashes in which there was an injury or fatality rose roughly 1 percent.

Wiefarich went on to note that it may be too early to tell whether speed is the ultimate factor.

"One year, even two years, is such a small snippet of time, and there’s a lot of factors that go into crash rates, even things you wouldn’t think about, like the economy,” Wieferich told Bridge. “People may be more likely to take more personal risks in a better economy than they do when things are slower.”